3-dimensional (“3D”) data sets may be generated from measuring points spanning in a 3D space such as spherical surface. The data sets are processed to provide useful information related to the 3-dimensional space. For example, the time-varying Event-Related Potential (“ERP”) data in cognitive neuroscience is measured from electrodes positioned on different locations at the scalp of a person. The ERP data collected allows scientist to observe human brain activity that reflects specific cognitive processes at a specific time. A comprehensive understanding of the complex temporal-spatial correlation of time-varying ERP, particularly when there are many data sets from 3D space generated over time, relies upon how the data sets are functionally interpreted and processed for visualization.